哈尔滨大剧院钢结构屋盖卸载模拟及应力监测

Unloading simulation and stress monitoring of steel roof of the Harbin Grand Theater

大跨空间钢结构施工卸载过程受力复杂。本文采用有限元软件Midas gen建立哈尔滨大剧院钢结构屋盖的有限元分析模型,对卸载进行有限元分析,制定了相应的合理卸载施工方案,为了保证卸载安全性,对关键杆件的应力变化进行了实时监测,并与有限元分析的结果进行了对比。通过对卸载过程的监测和分析,可见卸载方案是合理的,并且监测结果表明,复杂大跨度空间结构实际结构和有限元模型存在一些差异,这在监测结果中有所体现,模拟卸载得到的关键杆件应力在卸载过程中与监测应力有较大差异,杆件在卸载过程中存在偏心受压现象,但卸载完成,结构经过应力重分布稳定之后,监测杆件应力和数值模拟应力大体相当,所以,卸载过程的应力监测,是保证施工安全的一个有效方法。

The stress state of large span spatial steel structure in its unloading process during construction is complex.Unloading process of the steel roof of the Harbin grand theater is demonstrated in this paper.The finite element model of this structure was first established by using the software Midas Gen.Then the unloading process was simulated and unloading plan was made.In order to ensure the safety of unloading,the stress of critical bar in this structure was monitored.After that,the results form simulation and monitoring were compared.Both results of simulation and monitoring indicated that the unloading plan is reasonable.Through the comparison,it can be recognized that there is difference between the numerical model and the real model of the complex large span spatial structure.Also,the difference between the stresses of simulation and monitoring is observed.It is because that many bars are in eccentric compression state during unloading.However,after the unloading and stress redistribution in all bars,the stresses in simulation and monitoring are coincident each other well.Therefore it can be concluded that the stress monitoring during unloading is an effective method to ensure construction safety of large span spatial structure.